How long does it take for yeast to undergo alcoholic fermentation?

Answer 1

Fermentation begins immediately - I create yeast starters from grape juice and it doubles in size within 15 minutes sometimes. How long it lasts depends on several things:

1. Temperature - the warmer it is, the faster it ferments (if it's too hot the yeast will die). General rule... 75 degrees for red wine, 65 degrees for white wine during fermentation is the goal.

2. Sugar content - the more sugar that is in the liquid, the more the yeast has to work before it has eaten all the sugar and converted it to alcohol and CO2.
3. Yeast Variety and Pitch method - Different varieties of yeast work differently and ferment at different rates, and it also depends on if you just dump the yeast in or actually create a starter first.
4. PH level - again, different strains of yeast are more or less tolerant to different PH ranges
5. Nutrients - Yeast also reguires nutrients to grow and multiply. In red wine, the fermentation occurs on the skins so that you get a deep red color. Those skins give the yeast the nutrients to multiply and go crazy. White wine uses juice that is pressed before fermentation (no grape skins). As such, there is less nutrients for the yeast to grow in white wine. Most winemakers therefore add nutrients (you can buy it in a bottle) to their white juice before fermentation.

When I make wine, the fermentation is normally completed within 2-4 weeks (unless I perform a malolactic fermentation... that's a entirely different subject in itself). Of course, the wine then has to age for as long as possible before drinking, but that has nothing to do with fermentation - just flavor.

Answer 2

It depends on all the things previously mentioned...amount of sugar, yeast, conditions, etc.

For complete fermentation (*all* sugar consumed) can take a very long time...months even. About 80% is completed whithin the first 5 days. The rate is proportional to the amount available. Less available, the slower it goes, so it tapers down at the end, which is why the majority happens in the first week, but it takes 6+ to get it all...it's not linear.

Answer 3

Very much depending on the, sugar level(brix or beaume) temperature on the fermentation tank. i would prefer to keep it low & prolong the fermentation, which could help to astract more flavour from the fruits.

Answer 4

Around 6 weeks if you brewing your own . When the bubbles stop on your demijohn for wine , and when the specific gravity is correct for beer or lager. Hope this helps.

Answer 5

about as long as it will take you to get your stomach pumped after you drink it